Sounds of Spacetime:
A website that explains LIGO detections and gravitational-wave physics via the analogy between gravitational waves and audio signals. (Montclair State University)

LIGO Gravoscope:
An interactive tool that lets you compare visions of the Universe in a range of wavelengths.
Also shows locations of detected gravitational-wave signals. (Cardiff University Astronomy and Astronomy Instrumentation Groups)

Gravity Spy: a citizen-science project to help LIGO search for gravitational waves by improving glitch classification.

Einstein@Home: use your computer's idle processing time to help search for pulsars using gravitational wave, radio, and gamma-ray data.

At a glance

GW150914 signal observed by the twin LIGO observatories at Livingston, Louisiana, and Hanford, Washington. The signals came from two merging black holes, each about 30 times the mass of our sun, lying 1.3 billion light-years away. The top two plots show data received at Livingston and Hanford, along with the predicted shapes for the waveform. These predicted waveforms show what two merging black holes should look like according to the equations of Albert Einstein's general theory of relativity, along with the instrument's ever-present noise. Time is plotted on the X-axis and strain on the Y-axis.

Masses of LIGO/Virgo detections. LIGO and Virgo have observed the merger of several binary black holes and one binary neutron star. The black holes represent a new population with masses that are larger than what had been seen previously with X-ray studies alone. This plot shows the masses of the binary components before merger, as well as the mass of the merger remnant. It includes all confident detections following the release of data from the first and second LIGO/Virgo observing runs (the O1/O2 catalog). [Image credit: LIGO-Virgo/Northwestern Univ./Frank Elavsky]